The present invention relates to an intake system for a combustion engine with at least two rows of cylinder heads including an intake manifold for each of the cylinder head rows connected to pipes leading to cylinders, transverse pipes connecting the intake manifolds to one another, and an air supply duct leading to at least one of the transverse pipes, and in which each of the transverse pipes is equipped with a throttle valve to regulate air volume.
Intake systems featuring resonance turbocharging for optimal cylinder filling at various RPMs and loads are known from the prior art. German document DE 198 14 970 A1 describes an intake system in which, aided by an adjustable control mechanism with a continuous range, the resonance chamber volume can be precisely adapted load or RPM. Attached to the resonance chamber is a double-fluted intake manifold, which is situated downstream from a throttle valve connected to a common section of pipe. As a result of this configuration, the gas column can oscillate between the two cylinder heads according to the opening and closing of the intake valves situated at each cylinder head, thereby facilitating a dynamic supercharging of the combustion engine.
An intake system with adjustable resonance volume is known from German document DE 198 42 724 A1. In this design the resonance chambers for the cylinder head rows are connected to one another via two transverse ducts. Both transverse ducts feature throttle valves, through which the resonance frequency of the intake system can be adjusted to provide optimal filling of the cylinders. Two individual intake manifolds project from a transverse duct connecting both resonance chambers. At its junction with the transverse duct, each intake manifold features a throttle valve for regulating intake air volume.
An adjustable intake system is known from unpublished German patent application 103 21 323.6. As opposed to the system described in German document DE 198 42 724 A1, with its dual throttle valve construction, only one throttle valve is present in a common pre-intake line. Through this feature, the overall length of the intake ducting can be adjusted, because the common intake pipe connected to the two individual intake manifolds does not influence the distance covered by the oscillation of the gas column between the two resonance chambers. The air filter housing upstream from the throttle valve can therefore be better adapted to the available space and arranged in a simple manner among the engine components.
An object of the invention is the further improvement of the intake system in terms of cost and arrangement freedom while retaining functionality.
This object of the invention can be achieved by providing the air supply duct with a double-fluted distributor pipe leading to one of the transverse pipes and connected downstream of a throttle valve housing, and by having an interior wall, integrated into the distributor pipe, divide the interior of the distributor pipe into two interior ducts of virtually equal cross section.
Unlike the intake system design described in German document DE 103 21 323.6, the individual pipes leading to a transverse duct of the intake system are merged in a double-fluted distributor pipe, wherein an interior wall is integrated into the distributor pipe. The interior wall functions to divide the interior space of the distributor pipe into two interior ducts of virtually equal cross section. In this way, the dimensions and the material costs for the intake system are reduced in an advantageous manner. The distributor pipe is preferably made of a synthetic material, wherein the distributor pipe and interior wall can be produced simultaneously through injection molding.
Additional advantageous embodiments and further developments of the intake system are possible through additionally claimed features.
The throttle valve present in a first transverse duct is mounted via one end of its axle to the interior wall integrated in the distributor pipe. As a result, when the valves are open—during which time both intake manifolds are directly connected via the transverse duct—a minimal intake air resistance is present, because the valve axle is turned in the direction of the airflow.
An embodiment of the invention is further described and illustrated in the description and drawings.